Hitherto, disposable body warmers have been frequently used because they have excellent properties as a warming tool for the body, such as portability, safety, and convenience, and also because they are inexpensive. Typical disposable body warmers use an exothermic composition that generates heat in the presence of air, and a heat-keeping effect is produced through this heat-generating mechanism. However, the disposable body warmers generate characteristic odors attributable to the exothermic composition; this has been a cause of unpleasant odors specific to disposable body warmers.
Hitherto, perfuming of disposable body warmers and other heating tools has been reported. For example, Patent Literature 1 discloses adding a fragrance to the surface of a hitherto-known disposable body warmer, and promoting the volatilization and diffusion of the fragrance by utilizing the heat-generating mechanism of disposable body warmers. However, when a fragrance is added as above to a heating tool that uses a disposable body warmer, aroma originating from the fragrance changes, posing a problem in which the desired aroma cannot be fully enjoyed.
A heating tool to which aroma is imparted generates unpleasant odors attributable to the exothermic composition as the aroma changes. It is thus necessary to suppress the generation of unpleasant odors while maintaining a favorable aroma.
Additionally, heating tools are not only used immediately after their production, but also often used after a certain period of storage time. It is thus also important to suppress the generation of unpleasant odors and changes in aroma that occur during storage.